Co0.6Ni0.4S2/rGO Photocatalyst for One-Pot Synthesis of Imines from Nitroaromatics and Aromatic Alcohols by Transfer Hydrogenation

Abstract

Co0.6Ni0.4S2/rGO catalysts exhibit excellent photocatalytic performance for one-step synthesis of N-benzylideneaniline from nitrobenzene and benzyl alcohol by transfer hydrogenation, and the selectivity and yield of N-benzylideneaniline can reach as high as 93% and 77.2%, respectively. The reaction process for the synthesis of imines can be divided into two steps: benzyl alcohol is oxidized to benzaldehyde, while nitrobenzene is reduced to aniline; benzaldehyde and aniline are condensed to form imines. Under visible light irradiation, photo-induced electrons in Co0.6Ni0.4S2/rGO photocatalyst play an important role in activating nitrobenzene and benzaldehyde. Photo-induced holes are mainly responsible for the partial dehydrogenation of benzyl alcohol to benzaldehyde. Next, aniline molecules condense with benzaldehyde molecules to synthesize imine. The photocatalytic system provides an environmentally friendly for the synthesis of imines and supplies an alternative approach for hydrogen auto-transfer reactions.